THEMIS Newshttp://themis.asu.edu/news/116
enZoom around Gale Crater using your web browserhttp://themis.asu.edu/node/5991
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Zoom around Gale Crater using your browser </div>
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Explore Gale Crater, landing site for NASA&#039;s new Mars rover Curiosity, using your browser! </div>
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<p>A large mosaic of THEMIS images showing Gale Crater, the landing site for Curiosity, NASA's Mars Science Laboratory rover, is now available for would-be Martians to explore using their web browsers.</p><p>Gale Crater is 154 kilometers (96 miles) wide and it contains a 5-km (3-mi) high mound of layered sediments, which is a primary target for Curiosity. The mound is dubbed Mt. Sharp by scientists, who estimate the crater formed by a massive impact 3.5 to 4 billion years ago.</p><p>THEMIS is the <a href="http://themis.asu.edu/about/">Thermal Emission Imaging System</a>, a multiband visible and infrared camera on NASA's Mars Odyssey orbiter.</p><p>The mosaic, a product of the Mars Space Flight Facility in the School of Earth and Space Exploration at Arizona State University, is at: <a href="http://jmars.mars.asu.edu/maps/gale/gale.html" title="http://jmars.mars.asu.edu/maps/gale/gale.html">http://jmars.mars.asu.edu/maps/gale/gale.html</a>. This page also includes a link to download a .PNG copy of the whole image. (Caution &mdash; with a file size of 325 MB, downloads will be slow.)</p><p>The Gale Crater mosaic is woven together from 205 individual images, the vast majority of them THEMIS visual-wavelength images. (A few small holes were filled temporarily with images from the Context Camera (CTX) on Mars Reconnaissance Orbiter.) Such THEMIS images reveal details as small as 60 feet (18 meters) in size.</p><p>Because all the mosaic's images were taken before Curiosity landed, the rover is naturally not in the scene. In addition, although Curiosity is the largest payload ever sent to the Martian surface, the 10-foot-long rover is too small to be seen by THEMIS.</p><p>&quot;The THEMIS images were taken throughout the whole mission,&quot; says Jonathon Hill, the Mars researcher at ASU who assembled the mosaic. &quot;A lot of them were taken recently, after we started specifically targeting Gale when it became one of the possible landing sites. But other images go back nearly to the beginning of the mission in 2002.&quot;</p><p>In all, he says, it took about two and a half weeks to put it all together. &quot;The thing that made it take so long was that when you blow the image up that big, or when you zoom in that much, any misalignment of the images becomes very obvious.&quot; In the end, he had to align and custom fit most of the frames manually.</p><p>While the mosaic is fun to explore, it also has a scientific use. As Hill explains, &quot;The reason we decided to assemble such a large, comprehensive mosaic of Gale Crater was to give ourselves a better sense of the context around the landing site. This will help us to better understand what Curiosity sees and measures as it roves the surface.&quot;</p><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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NewsMon, 06 Aug 2012 07:00:00 +0000Administrator5991 at http://themis.asu.eduTHEMIS data suggest early Gale Crater targets for roverhttp://themis.asu.edu/node/5990
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THEMIS points out Curiosity rover targets </div>
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THEMIS data covering Gale Crater point to hardened sediments near an alluvial fan that will likely become an early target for NASA&#039;s Curiosity rover. </div>
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<p>NASA chose Gale Crater as the landing site for Curiosity, the new Mars Science Laboratory rover, because the crater contains a variety of water-related minerals and features. These enhance the likelihood of the rover finding geological deposits with organic compounds, a key ingredient in the search for life, past or present, on Mars.</p><p>Gale Crater spreads 154 kilometers (96 miles) wide, and it contains a 5-km (3-mi) high stack of layered sediments. Scientists estimate the crater formed by a massive impact 3.5 to 4 billion years ago. However, the origin of the layered sediment stack, dubbed Mt. Sharp, is unknown.</p><p>The Thermal Emission Imaging System (<a href="http://themis.asu.edu/about">THEMIS</a>) is a multiband visible and infrared camera on NASA's Mars Odyssey orbiter. THEMIS has produced <a href="http://themis.asu.edu/landingsites/mslsite_06">data</a> about the surface materials on the Gale Crater floor that Curiosity's science team is using to map locations that may become early targets for the rover's instruments.</p><p>THEMIS imaged the crater by day and night at heat-sensitive infrared wavelengths. The contrast between day and night temperatures indicates how soft or hard the ground is. Surfaces with sand, dust, or other fine-grain materials cool off quickly at night, while outcrops of rock and hardened sediments cool more slowly.</p><p>Researchers then combine day and nighttime views and apply false colors to map the different regions. Fine-grain sediments appear in cool colors, harder materials in warm tones (see at right).</p><p>The landing ellipse for Curiosity touches a feature geologists have mapped as an alluvial fan. Similar to alluvial fans commonly found in desert regions of Earth, it formed when water flowed through Gale's northern rim and washed sediments onto the floor. Within the ellipse, but just beyond the farthest edge of the fan lies a broad patch mapped in reddish tints.</p><p>&quot;We're not sure what these materials are made of,&quot; said Project Scientist John Grotzinger (Caltech), head of the science team, at a NASA press briefing, August 2, 2012. &quot;But they could be loose surface materials that have become cemented by water from the fan.&quot;</p><p>Curiosity will land somewhere within the oval outlined in yellow. The rover even has a good chance of actually landing right on top of the sediments. And even if it doesn't, notes Grotzinger, these materials will lie within a short drive and will be visited soon after the landing.</p><p>Said Grotzinger, &quot;It all suggests we've got some cool geology to explore.&quot;</p>NewsThu, 02 Aug 2012 20:02:03 +0000Administrator5990 at http://themis.asu.eduTHEMIS celebrates a decade's discoverieshttp://themis.asu.edu/node/5853
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Ten years&#039; science imaging at Mars </div>
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In the last decade, the THEMIS camera has circled Mars nearly 45,000 times and taken more than half a million images. </div>
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<p><span style="font-weight:normal">Ten years ago, on February 19, 2002, the Thermal Emission Imaging System (<a href="http://themis.asu.edu/about">THEMIS</a>), a multi-band camera on NASA's Mars Odyssey orbiter, began scientific operations at the Red Planet. Since then the camera has circled Mars nearly 45,000 times and taken more than half a million images at infrared and visible wavelengths.</span>&nbsp;</p> <div><span style="font-weight:normal">&quot;THEMIS has proven itself a workhorse,&quot; says Philip Christensen, the camera's designer and principal investigator. Christensen is a Regents' Professor of geological sciences in the School of Earth and Space Exploration, part of Arizona State University's College of Liberal Arts and Sciences. &quot;It's especially gratifying to me to see the range of discoveries that have been made using this instrument.&quot;</span></div> <div>&nbsp;</div> <div><span style="font-weight:normal">Highlights of science results by THEMIS over the past 10 years include:</span></div><div>&nbsp;</div> <div><span style="font-weight: normal;">&bull; Confirming that <a href="https://themis.mars.asu.edu/node/5390">hematite is widespread on Meridiani Planum</a>, which led NASA to send one of its Mars Exploration Rovers there</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; Discovering <a href="https://themis.mars.asu.edu/node/5391">CO<sub>2</sub> gas jets</a> at the south polar ice cap in spring</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; Discovering <a href="https://themis.mars.asu.edu/news/salt-deposits-found-martian-highlands">chloride salt deposits</a> across the planet</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; Making the <a href="https://themis.mars.asu.edu/news/themis-camera-yields-best-mars-map-ever">best global image map of Mars</a> ever done</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; Identifying <a href="https://themis.mars.asu.edu/news/themis-helps-phoenix-land-safely-mars">safe landing sites for NASA's Mars Phoenix lander</a> by finding the locations with the fewest hazardous boulders</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; <a href="https://themis.mars.asu.edu/dust_activity_monitor">Monitoring dust activity</a> in the Martian atmosphere</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; Discovering that a large crater, <a href="https://themis.mars.asu.edu/node/5394">Aram Chaos, once contained a lake</a></span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; Discovering that Mars has <a href="https://themis.mars.asu.edu/node/5399">more water-carved channels</a> than previously thought</span></div><div>&nbsp;</div><div><span style="font-weight: normal;">&bull; <a href="https://themis.mars.asu.edu/node/5397">Discovering dacite on Mars</a>, a more evolved form of volcanic lava not previously known on the Red Planet</span></div><div>&nbsp;</div><div><span style="font-weight:normal">THEMIS combines a 5-wavelength visual imaging system with a 9-wavelength infrared imaging system. By comparing daytime and nighttime infrared images of an given area, scientists can determine many of the physical properties of the rocks and soils on the ground.</span></div><div>&nbsp;</div><div><span style="font-weight:normal">Mars Odyssey has a two-hour orbit that is nearly &ldquo;Sun-synchronous,&rdquo; meaning that Odyssey passes over the same part of Mars at roughly the same local time each day. In September 2008 its orbit was shifted toward an earlier time of day, which enhanced THEMIS' mineralogical detection capability.</span></div><div>&nbsp;</div><div><span style="font-weight:normal">Says Christensen, &quot;Both Odyssey and THEMIS are in excellent health and we look forward to years more science with them.&quot;</span></div><div>&nbsp;</div><div><span style="font-weight:normal">NASA launched the <a href="http://mars.jpl.nasa.gov/odyssey/">Mars Odyssey</a> spacecraft April 7, 2001, and it arrived at Mars October 24, 2001. On arrival the spacecraft spent several months in a technique called aerobraking, which involved dipping into the Martian atmosphere to adjust its orbit. In February 2002, science operations began.</span></div><div>&nbsp;</div><div><span style="font-weight:normal">The Mars Odyssey project is managed by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems in Denver built the spacecraft, and JPL and Lockheed Martin collaborate on operating it.</span></div>NewsTue, 28 Feb 2012 21:04:40 +0000Administrator5853 at http://themis.asu.eduIn memory: Planetary geologist Ronald Greeleyhttp://themis.asu.edu/node/5770
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Ronald Greeley </div>
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Ronald Greeley, a Regents&#039; Professor of Planetary Geology at ASU who contributed significantly to our understanding of the solar system, died October 27, in Tempe. </div>
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<p>Ronald Greeley, a Regents' Professor of Planetary Geology at Arizona State University who was involved in lunar and planetary studies since 1967 and who contributed significantly to our understanding of planetary bodies within our solar system, died Oct. 27, in Tempe. He was 72.</p>
<p>As the son of a military serviceman, Greeley moved around a great deal as child. As a result he saw many different geological landforms and it was no surprise that when he went to college, he majored in geology. Greeley earned undergraduate and graduate degrees from Mississippi State University. After receiving his doctorate in 1966 at the University of Missouri in Rolla he worked for Standard Oil Company of California as a paleontologist.</p>
<p>Through military duty, he was assigned to NASA's Ames Research Center in 1967 where he worked in a civilian capacity in preparation for the Apollo missions to the Moon. He stayed on at NASA to conduct research in planetary geology. </p>
<p>"I had been on sabbatical at NASA Ames Research Center working on the analysis of lunar samples, and I saw Ron and I saw potential," recalls Carleton Moore, founding director of ASU’s Center for Meteorite Studies. "When I got the opportunity, I hired him."</p>
<p>Greeley began teaching at ASU in 1977 with a joint professorship in the department of geology and the Center for Meteorite Studies. He studied wind processes on Earth and other planets and conducted photogeological mapping of planets and satellites among other research projects. In 1986, Greeley left the Center for Meteorite Studies to serve as chair of the department of geology. </p>
<p>"It was exciting to have him here; he was a major step in advancing space at ASU. He was the first one that came that did missions and experiments on planetary bodies," says Moore. "He was really the first person to reach out to the other planets. And then he hired Phil Christensen.”</p>
<p>"Ron Greeley was indisputably one of the founders of planetary science, and the influence he has had, both through his own work and through the students and colleagues that he guided and mentored, touches virtually all aspects of this field," says Christensen, a Regents' Professor in the School of Earth and Space Exploration in ASU’s College of Liberal Arts and Sciences. </p>
<p>"Ron played a major role in my career," says Christensen. "I came to ASU specifically to work with Ron after receiving my graduate degree, and I have remained at ASU for 30 years largely because of the remarkable environment that Ron created here to foster planetary science as an extension of geology."</p>
<p>Greeley, a pioneer in the planetary geology field, served as the director of the NASA-ASU Regional Planetary Image Facility and principal investigator of the Planetary Aeolian Laboratory at NASA-Ames Research Center. He served on and chaired many NASA and National Academy of Science panels and he was involved in nearly every major space probe mission flown in the solar system since the Apollo Moon landings. Mission projects included the Galileo mission to Jupiter, the Magellan mission to Venus, and the Shuttle Imaging Radar orbiter around Earth. He was also part of the data analysis program for the Voyager 2 mission to Uranus and Neptune. His projects focused on the moons of these distant bodies. </p>
<p>Passionate also about Mars exploration, he was involved with several missions to the Red Planet, including Mariners 6, 7, and 9, Viking, Mars Pathfinder, Mars Global Surveyor, and the Mars Exploration Rovers. He was a co-investigator for the camera system onboard the European Mars Express mission.</p>
<p>Former students scattered throughout the universities and research institutes of this country provide testimony to his influence on planetary geology.</p>
<p>"As I began my research career, Ron reminded me of the old adage: 'A journey of 1,000 miles begins with a single step.' I am fortunate to have had Ron there walking beside me," says Robert Pappalardo, senior research scientist at NASA's Jet Propulsion Laboratory. Greeley served as Pappalardo's advisor. After receiving his doctorate from ASU in 1994, Pappalardo worked with Greeley for a year as a postdoc. Since about 2002, the two worked together on defining the science basis for Europa mission studies.</p>
<p>"Ron was a gentleman, a statesman, a mentor, a scholar," says Pappalardo. "Not a day goes by that I don't think, in some situation, 'What would Ron Greeley do?'"</p>
<p>"Ron was a profoundly influential scientist whose imprint on planetary science will live on through his body of research and the many students he taught and mentored. He was a wonderful friend and colleague. We were fortunate to have known him and will miss him terribly," says Kip Hodges, founding director of the School of Earth and Space Exploration. Greeley served a year as interim director of the school before Hodges joined ASU.</p>
<p>"Ron was a very good friend of mine for many years, an incredible leader in planetary science, and the founder and guiding force for planetary science here at ASU. His leadership, friendship, and vision will be sorely missed," says Christensen.</p>
<p>Greeley's work lives on in proposed missions to Europa (a moon of Jupiter), and in the numerous students he mentored who today play pivotal roles in space science exploration efforts.</p>
<p>Greeley is preceded in death by his daughter, Vanessa. He is survived by his wife Cindy and his son, Randall (Lidiette). He leaves behind three grandchildren. </p>
<p>A Facebook page has been dedicated to Professor Greeley:<br />
<a href="http://www.facebook.com/profile.php?id=100003109532235&amp;sk=wall" title="http://www.facebook.com/profile.php?id=100003109532235&amp;sk=wall">http://www.facebook.com/profile.php?id=100003109532235&amp;sk=wall</a></p>
NewsFri, 28 Oct 2011 23:12:01 +0000Administrator5770 at http://themis.asu.eduTHEMIS keeps an eye on Mars for dusthttp://themis.asu.edu/dust_activity_monitor
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THEMIS monitors Mars dust </div>
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Scientists are using THEMIS to detect seasonal and yearly changes in dust activity and to track the development of dust storms. </div>
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<p>Summertime is coming to the south of Mars, and days are growing longer and warmer. This is not good news, however &mdash; and the reason why can be given in a single word: <em>dust</em>.</p><p>Scientists at Arizona State University's Mars Space Flight Facility are using the Thermal Emission Imaging System (<a href="http://themis.asu.edu">THEMIS</a>) on NASA's Mars Odyssey orbiter to detect seasonal and yearly changes in the amount of dust veiling the Red Planet's atmosphere. THEMIS is a multiband camera that works at 9 infrared wavelengths and five visual ones.</p><p>The scientists are using an algorithm that estimates the dust opacity at an infrared wavelength of 9 micrometers. The most recent THEMIS dust maps are at right (latest at top; click to enlarge). Dust maps are also available going back farther that display the <a href="http://themis.mars.asu.edu/dust_maps">lower part of the dust range</a> with enhanced sensitivity. (This magnifies the amount of activity, making it easier to see when activity is less.) The accompanying data coverage figures show where individual THEMIS dust measurements have been made; the dust maps are extrapolations from these.</p><p>Below the current dust maps at right are movies made with an earlier instrument, the Thermal Emission Spectrometer (TES) on NASA's Mars Global Surveyor orbiter. Data from TES overlapped in time with THEMIS, which let scientists calibrate THEMIS as a dust monitor.</p><p>The picture emerging from THEMIS data shows dust activity increasing as the Martian season nears southern summer, which begins April 9, 2011. (One month earlier, Mars comes closest to the Sun in its orbit.)</p><p>&quot;Dust storms on Mars are driven by solar heat,&quot; explains Philip Christensen, Regents' professor of geological sciences and the THEMIS camera's designer and principal investigator. &quot;Like winds on any planet, air flows from where it's warm to where it's colder.&quot;</p><p><strong>Dust in all the corners</strong></p><p>For more than a billion years, Mars has lacked oceans or other large bodies of liquid water to trap windblown sediments. As a result, the entire Martian surface is dusty, with very few places completely bare of it for long. This provides ample fine material for winds to lift into the air.</p><p>&quot;Mars travels in a very elliptical orbit,&quot; Christensen says. &quot;And it's closest to the Sun at the time of southern summer. That's when the heating is greatest, the winds are strongest, and traditionally, that's when the big global dust storms occur.&quot;</p><p>He adds, however, that atmospheric activity also includes regional dust storms that erupt throughout the Martian year. &quot;It's not like there's no dust activity outside of southern summer.&quot;</p><p>Dust storms on Mars, which occur on local, regional, and global scales, dwarf anything seen on Earth. On Mars a &quot;local&quot; storm means one that's the size of Arizona, and a regional storm could cover the entire United States.</p><p>Dust kicked aloft by winds affects operations for all spacecraft working at Mars. The fleet currently includes two NASA rovers on the ground (Spirit and Opportunity), plus three orbiters, two of which belong to NASA (Mars Odyssey and Mars Reconnaissance Orbiter) and one from the European Space Agency (Mars Express).</p><p>Christensen says that scientists have a couple of options when dust activity grows. &rdquo;The main thing we do is look at past activity to identify the places most likely to be dusty, and then just not image there. And make a note not to send future rovers to that place.&quot;</p><p>Moreover, he adds, &quot;during hazy periods, we take fewer images at visual wavelengths and more infrared because they are less sensitive to the dust.&quot;</p><p><strong>Going global</strong></p><p>Over the <a href="http://themis.mars.asu.edu/themis_all_star_images">nine years</a> that THEMIS has operated at Mars, data from it and its predecessors, plus instruments on other spacecraft, have increased scientists' knowledge of how dust storms grow and develop.</p><p>Explains Christensen, &quot;People used to think there's just one source region and it blew dust all around the planet. But we have a better picture now.&quot;</p><p>Activity might start in Hellas, he says, &quot;a large, deep impact basin in the Southern Hemisphere containing loads of dust. Again and again, dust activity would migrate out &mdash; then die. Eventually, though, dust starts drifting around the planet, and a week later we'll see four, five, or six of these major regional storms popping off.&quot;</p><p>A major goal for scientists is to understand how the storms originate.</p><p>&quot;There are some ideas,&quot; says Christensen. &quot;One idea is that there's feedback going on. One year you have a big storm and lots of dust eventually falls out onto the surface. This brightens the ground so that next year it doesn't get as hot, and thus it doesn't generate as much wind. It takes a while for the dust to blow away and leave a dark surface. But when that finally happens, the surface gets really hot, and then, boom, you get a big storm again.&quot;</p><p>He admits, &quot;It's hard to prove this idea or disprove it, but it's rare to have two global storms in two successive Mars years. So the prediction is that if last year &mdash; 2009 &mdash; was a bad year, then this year &mdash; 2011 &mdash; won't be as bad.&quot;</p><p>In the big picture, he says, it's interesting that Mars seems to remain right at the threshold of triggering global storms.</p><p><strong>Finer than talcum powder</strong></p><p>Mars dust isn't like most Earth dust; the particles are much smaller. &quot;Even talcum powder is about six times larger than the average Mars dust particle,&quot; explains Christensen. &quot;If you think about it, however, that makes sense because the dust can hang around in a really thin atmosphere, only one percent as dense as Earth's.&quot;</p><p>The dust is also telling us something about Mars' climate history, Christensen says, because there ought to be even more of it than scientists find.</p><p>&quot;There's a good question why Mars isn't a billiard-ball planet covered by a kilometer of dust,&quot; he says. &rdquo;Well, maybe throughout most of its history, Mars has had too thin an atmosphere to make dust or initiate saltation or wind abrasion. No dust devils, no storms.&quot;</p><p>In this scenario, Christensen says, maybe the atmosphere cycles in and out. &quot;At the top of the cycle &mdash; like now &mdash; perhaps there's enough atmosphere that dust erosion activity can operate. But over geologic time, the atmosphere stays mostly in a regime where nothing happens.&quot;</p><p>If you take our best guess as to how much dust is being created now, he says, &quot;and you multiply that times 4.5 billion years, you get 100 meters of dust covering everywhere on the planet.&quot;</p><p>But, he concludes, &quot;If Mars is actively making dust only 2% of the time, you'd get 2 meters of dust &mdash; and well, that's about right.&quot;</p>http://themis.asu.edu/dust_activity_monitor#commentsatmospheredustmarsTue, 11 Jan 2011 17:27:20 +0000Administrator5555 at http://themis.asu.eduTHEMIS: All-Star imageshttp://themis.asu.edu/themis_all_star_images
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THEMIS: All-Star images </div>
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THEMIS presents a hit parade slide show of images, as NASA&#039;s Mars Odyssey orbiter becomes the longest-duration Mars spacecraft. </div>
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<p>A space exploration milestone has fallen. On December 15, 2010, NASA's Mars Odyssey orbiter became the longest-running spacecraft at Mars, breaking the 3,340-day record set by NASA's Mars Global Surveyor, which operated at Mars from September 11, 1997 to November 2, 2006. NASA launched the Mars Odyssey orbiter on April 7, 2001, and it arrived at Mars October 24, 2001.</p><p>Odyssey made its most famous discovery &ndash; evidence for copious water ice just below the dry surface of Mars &ndash; during its first few months, and it finished its radiation-safety check for future astronauts before the end of its prime mission in 2004. The bonus years of extended missions since then have enabled many accomplishments that would not have been possible otherwise.<br /><br />&quot;The extra years have allowed us to build up the highest-resolution maps covering virtually the entire planet,&quot; says Odyssey Project Scientist Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif. These maps are the product of the Thermal Emission Imaging System (<a href="http://themis.asu.edu">THEMIS</a>), a multiband camera which began mapping February 19, 2002.</p><p>To note Odyssey's breaking the longevity record, the THEMIS team, working with NASA, has prepared a <a href="http://www.nasa.gov/mission_pages/odyssey/images/all-stars.html">slide show</a> of remarkable images taken by the instrument.</p><p><strong>Heat-Seeking Eye</strong></p><p>Swooping around the Red Planet in a 2-hour orbit locked on the Sun, Odyssey makes two passes over any given spot on the ground each Martian day, once at a local time of about 4 p.m. and again in the predawn hours around 4 a.m. As a result, THEMIS scans the planet day and night.</p><p>&quot;The day-night contrast is highly important for how THEMIS operates,&quot; says Philip Christensen, the instrument's designer and Principal Investigator. Christensen, a Regents' professor of geological science in Arizona State University's School of Earth and Space Exploration, is the director of the Mars Space Flight Facility on the Tempe campus.</p><p>THEMIS, he explains, is a camera that images Mars simultaneously in five visual and 10 infrared bands or colors. &quot;The daily temperature differences between afternoon and the predawn night can tell scientists a lot about nature of the surface materials &mdash; whether they're durable and compacted like rock, or loose and friable like sand and dust.&quot;</p><p>For example, rock is slower than sand to warm up during daytime, but it holds heat much better at night. When THEMIS images the ground late at night, exposures of rock and hard sediments glow with residual warmth, while sandy and dusty areas &mdash; much warmer than rock during the day &mdash; look dark and cold to THEMIS' heat-sensing eye.</p><p>In addition, Christensen notes, &quot;By comparing how the surface looks at all of THEMIS' different wavelengths, we gain insights about the mineralogy of the surface rocks and sediments.&quot; This information is highly important, he says, for NASA's goal of looking for Martian environments that might have once harbored life.</p><p><strong>Mars: the Big Picture</strong></p><p>One of THEMIS' most important results is the <a href="http://themis.asu.edu/news/themis-camera-yields-best-mars-map-ever">best map of Mars</a> ever compiled. &quot;Parts of Mars have been mapped at higher resolution by other instruments,&quot; says Christensen, &quot;but this is the most detailed map so far that covers the whole planet.&quot; Made by assembling nearly 21,000 individual images, it shows Mars at a resolution of 100 meters (330 feet) per pixel.</p><p>How long will Mars Odyssey and THEMIS continue? The spacecraft's supply of maneuvering fuel can keep it operating for years to come, and THEMIS remains in fine working order. Although THEMIS has mapped Mars at 100 meters' resolution, mission scientists plan to expand the area of Mars mapped by THEMIS at visual wavelengths, where the instrument's resolution is 18 meters (60 feet).</p><p>NASA has planned future work for Odyssey, in addition to having the orbiter continue its own science and its ongoing relay service for the Mars Exploration Rover mission. If needed, controllers will adjust Odyssey's orbit so the spacecraft is in a favorable position for a communication relay role during the August 2012 landing of NASA's next rover, the Mars Science Laboratory (MSL).</p><p>Says Christensen, &quot;THEMIS provides a crucial link between the early whole-planet views from Mars Global Surveyor and the highly focused and detailed studies of later instruments, both from orbit and on the Martian surface.&quot;</p>NewsThu, 09 Dec 2010 18:10:46 +0000Administrator5530 at http://themis.asu.eduPutting the spin on Marshttp://themis.asu.edu/news/putting-spin-mars
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Putting the spin on Mars </div>
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Wrapping spacecraft data onto Mars globes gives new perspectives on the Red Planet. </div>
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<p>Mars Space Flight Facility scientists and researchers are creating movies out of datasets that cover all of Mars. The goal is to explore a new way to use various all-Mars datasets collected by spacecraft. Wrapping datasets around a Mars globe that shows the basic landforms lets scientists study how various properties relate on a global scale.</p><p>The global tour provides an overview of eight datasets, each of which is available (links below) as stand-alone video clip.</p><p><img width="107" hspace="5" height="107" border="1" align="left" src="/files/videos/MVglobalTN.png" alt="" /></p> <p><strong>Mars Global Datasets Tour</strong><br />The data in the video show the telescopic view of Mars from Earth, the planet's albedo (brightness), its color, its topography, its ancient magnetism, its abundance of elemental potassium, its thermal inertia, and its global mineralogy. Then the scene zooms in, eventually stopping at Syrtis Major, a large, low volcano.</p><p><a href="/files/videos/Mars_global_data_movie.mov">Download</a> (1:23, Quicktime, <strong>28.5M</strong>) or watch on <a href="http://www.youtube.com/watch?v=2rlzsk0XyCQ">YouTube</a></p><p><strong>Mars Telescopic View</strong> <img width="107" hspace="5" height="107" border="1" align="left" src="/files/videos/MVtelescopeTN.png" alt="" /><br />This video clip shows the work of British artist and amateur astronomer Nathaniel Green (1823-1899) from the favorable 1877 opposition. The labels are upside down because Green's observations, published in the <em>Memoirs of the Royal Astronomical Society</em> for 1877-79, place south at top, matching the view in a telescope.</p><p><a href="/files/videos/Mars_telescopic_movie.mov">Download</a> (0:32, Quicktime, 5.7M) or watch on <a href="http://www.youtube.com/watch?v=v8DCf-VYwoA">YouTube</a></p><p><img width="107" hspace="5" height="107" border="1" align="left" src="/files/videos/MValbedoTN.png" alt="" /> <strong>Mars Albedo</strong><br />This video shows the global visual albedo (brightness) variations across Mars, as recorded by the Thermal Emission Spectrometer (TES) on NASA's Mars Global Surveyor orbiter.</p> <p>&nbsp;<a href="/files/videos/Mars_albedo_movie.mov">Download</a> (0:32, Quicktime, 4.8M) or watch on <a href="http://www.youtube.com/watch?v=BNyMet1wz7U">YouTube</a>&nbsp;</p><p><strong><img width="107" hspace="5" height="107" border="1" align="left" src="/files/videos/MVvikingTN.png" alt="" />Mars Color</strong><br />Between 1976 and 1982, NASA's twin Viking Orbter spacecraft made the first pole-to-pole image survey of Mars in color. Those images are here wrapped around a shaded-relief globe showing the planet's topography.</p> <p><a href="/files/videos/Mars_color_movie.mov">Download</a> (0:32, Quicktime, 4.1M) or watch on <a href="http://www.youtube.com/watch?v=Vzfga85ytW8">YouTube</a>&nbsp;</p> <p><img width="107" hspace="5" height="107" border="1" align="left" src="/files/videos/MVmolaTN.png" alt="" /><strong>Mars Topography</strong><br />The Mars Observer Laser Altimeter (MOLA) instrument on NASA's Mars Global Surveyor made the best map of Martian topography to date. Colors show elevations &mdash; &quot;sea level&quot; lies where yellow turns to green &mdash; while MOLA data and shading reveal the planet's basins, volcanos, and valleys.</p><p><a href="/files/videos/Mars_MOLA_topo_movie.mov">Download</a> (0:32, Quicktime, 5.7M) or watch on <a href="http://www.youtube.com/watch?v=DXUzHGLObUA">YouTube</a></p><p><strong>Mars Remanent Magnetism</strong> <img width="107" hspace="5" height="107" border="1" align="left" src="/files/videos/MVmagTN.png" alt="" /><br />Today Mars has no global magnetic field. However, some areas of ancient terrain have traces of the field that was active when the rocks formed. Red shows where the strongest residual magnetism lies.&nbsp;</p> <p><a href="/files/videos/Mars_mag_movie.mov">Download</a> (0:32, Quicktime, 7.3M) or watch on <a href="http://www.youtube.com/watch?v=7Lw6sz4HQ28">YouTube</a>&nbsp;</p> <p>&nbsp;<img width="107" hspace="5" height="107" border="1" align="left" alt="" src="/files/videos/MVabundanceTN.png" /><strong>Mars Elemental Abundances</strong><br />The Gamma-Ray Spectrometer (GRS) on NASA's Mars Odyssey orbiter has mapped the abundance of numerous elements (here: potassium) in the shallow subsurface layers.</p> <p><a href="/files/videos/Mars_abundance_movie.mov">Download</a> (0:32, Quicktime, 4.2M) or watch on <a href="http://www.youtube.com/watch?v=qnrfr_BcKRQ">YouTube</a>&nbsp;</p> <p><strong><img width="107" hspace="5" height="107" border="1" align="left" alt="" src="/files/videos/MVthermalTN.png" />Mars Thermal Inertia</strong><br />Thermal inertia is the resistance of materials to temperature changes. Solid rock and hard sediments have high thermal inertia values (mapped in warm tones), while sand and dust have lower values (cool tones).This data set comes from the Thermal Emission Spectrometer (TES) on NASA's Mars Global Surveyor orbiter.</p><p><a href="/files/videos/Mars_thermal_movie.mov">Download</a> (0:32, Quicktime, 6.2M) or watch on <a href="http://www.youtube.com/watch?v=C4aBq_9pVdM">YouTube</a></p><p><strong><img width="107" hspace="5" height="107" border="1" align="left" alt="" src="/files/videos/MVmineralTN.png" />Mars Mineralogy</strong><br />Data from the Thermal Emission Spectrometer (TES) on NASA's Mars Global Surveyor orbiter, taken at 10 infrared wavelengths, lets scientists create maps showing where various types of mineral predominate at the Martian surface. This globe shows the distribution of the igneous mineral plagioclase feldspar, an important component of basalt rock.</p> <p><a href="/files/videos/Mars_mineralogy_movie.mov">Download</a> (0:32, Quicktime, 9.9M) or watch on <a href="http://www.youtube.com/watch?v=FRU0cHb31JM">YouTube</a></p> <p>&nbsp;</p> <p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p>NewsWed, 10 Nov 2010 15:35:22 +0000rburnham5474 at http://themis.asu.eduTHEMIS camera yields best Mars map everhttp://themis.asu.edu/news/themis-camera-yields-best-mars-map-ever
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THEMIS camera yields best Mars map ever </div>
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The best Mars map ever assembled is now online for planetary scientists and armchair astronauts alike — and citizen scientists are invited to help make it even better. </div>
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<p><span style="color: black;">The best Mars map ever made is now available online for planetary scientists and armchair astronauts alike. </span>And citizen scientists are invited to help make it even better.</p><p><span style="color: black;">W</span>ebsites deve<span style="color: black;">loped recently at Arizona State University's Mars Space Flight Facility, in collaboration with NASA, the Jet Propulsion Laboratory, and Microsoft, make it easy for anyone to trek the craters, volcanoes, and dusty plains of Earth's small red neighbor world.</span>&nbsp;</p> <div>&quot;We've assembled the best global map of Mars to date,&quot; says Philip Christensen, Regents' Professor of geological sciences in the School of Earth and Space Exploration, part of the College of Liberal Arts and Sciences. &quot;And we made it available via the Internet so everyone can help make it better.&quot;</div> <div>&nbsp;</div> <div>The map is accessible as an interactive <a href="http://jmars.mars.asu.edu/maps/?layer=thm_dayir_100m_v11">zoomable global map</a>, which is the easiest format for most viewers to use. (Advanced users with large bandwidth, powerful computers, and sophisticated software capable of handling gigabyte images, can <a href="http://www.mars.asu.edu/data/thm_dir_100m">download the map in sections</a> at full resolution.)</div> <div>&nbsp;</div> <div>The maps show Mars as if sliced from a globe, unwrapped, and flattened out on a table. Nearly 21,000 <span style="color: black;">individual images have been smoothed, blended, fitted together, and cartographically controlled to make a giant mosaic that Web viewers can zoom into and scroll around. The few missing pieces show where clouds and poor lighting have thus far prevented map-quality imaging; these places are high on mission planners' must-image targeting list.</span></div> <div>&nbsp;</div> <div>&quot;Portions of Mars have been mapped at higher resolution,&quot; says Christensen, &quot;but this is the most detailed map so far that covers the planet.&quot;</div> <div>&nbsp;</div> <div>All the map images come from t<span style="color: black;">he Thermal Emission Imaging System (<a href="http://themis.asu.edu/about">THEMIS</a>), a multi-band infrared and visual camera on NASA's Mars Odyssey orbiter. The smallest surface details visible when you zoom all the way in are 100 meters, or 330 feet, wide.</span></div> <div>&nbsp;</div> <div>The 100-meter map has been in the making since THEMIS observations began eight years ago. &quot;We tied the images to the cartographic control grid provided by the U.S. Geological Survey, which also modeled the THEMIS camera's optics,&quot; says Christensen, who is the principal investigator for THEMIS. &quot;This let us remove instrument distortion, so features on the ground <span style="color: black;">are correctly located to within a few pixels.&quot; </span></div> <div>&nbsp;</div> <div>The new map lays the framework for global studies of properties such as the mineral composition and physical nature of the surface materials. In addition, it is helping NASA mission planners choose targets for aiming instruments on the Mars Reconnaissance Orbiter. And the map also plays a role in evaluating potential landing sites for NASA's next Mars rover, the Mars Science Laboratory, due for launch in late 2011.</div> <div>&nbsp;</div> <div><b>Making the good even better</b></div> <div>&nbsp;</div> <div>But every map, however good, can still be improved and this is no exception. &quot;Computer-made maps have gone about as far as they can,&quot; says Christensen. &quot;Now it's the turn for citizen scientists.&quot;</div> <div>&nbsp;</div> <div>He adds, &ldquo;With the help of people from around the world, we can increase the accuracy of the global Mars map for Red Planet explorers everywhere.&quot;</div> <div>&nbsp;</div> <div>NASA's <a href="http://beamartian.jpl.nasa.gov">Be A Martian</a> website, developed in cooperation with Microsoft, offers an easy and engaging way for would-be Mars mappers to do exactly this. ASU is regularly contributing newly taken THEMIS images to the Be A Martian &quot;Map Room,&quot; where the public can help by hand-aligning new images, placing them within a pixel&rsquo;s accuracy.</div> <div>&nbsp;</div> <div><b><span style="color: black;">Mars mission album</span></b></div> <div>&nbsp;</div> <div><span style="color: black;">The origins of the new global map lie in the work of previous Mars missions, which began imaging the Red Planet decades ago. Two new websites developed at ASU provide a wide window into the gigantic collection of images taken by earlier Mars missions. </span></div> <div>&nbsp;</div> <div><span style="color: black;">Christensen explains: &quot;These websites present</span><span style="color: black;"> all the images taken by cameras aboard Mars-orbiting </span>space probes, starting with Viking in 1976. The image collection, regularly updated, also includes those from current missions, such as Europe's Mars Express, and NASA's Mars Odyssey and Mars Reconnaissance Orbiter.&quot;</div> <div>&nbsp;</div> <div>The new Mars Image Explorer, he says, lets viewers find images in either of two ways. Viewers can click on a map of Mars &mdash; or they can specify various key properties such as latitude and longitude, spacecraft orbit number, date, or viewing conditions. Viewers can check out the Explorer by <a href="http://viewer.mars.asu.edu">selecting key properties</a><span style="color: black;"> </span><span style="color: black;"> or by clicking on a <a href="http://themis.asu.edu/maps">mission-specific Mars map</a></span><span style="color: black;">.</span></div> <div>&nbsp;</div> <div><span style="color: black;">The broad purpose underlying all these sites is making Mars exploration easy and engaging for everyone, explains </span>Christensen.</div> <div>&nbsp;</div> <div>&quot;We're <span style="color: black;">trying to create a user-friendly interface between the public and NASA's Planetary Data System, which does a terrific job of collecting, validating, and archiving data. Our focus lies in providing easy access to Mars images for the general public and scientists alike.&quot;</span></div><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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Fri, 23 Jul 2010 17:59:56 +0000cyates111 at http://themis.asu.eduiPhone app delivers daily THEMIS Mars imageshttp://themis.asu.edu/news/iphone-app-delivers-daily-themis-mars-images
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iPhone app delivers daily THEMIS Mars images </div>
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A free iPhone app delivers THEMIS Images of the Day to your device. </div>
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<p>Feel a buzz in your pocket? That's Mars calling your iPhone.&nbsp;</p> <div>Thanks to a new &mdash; and free &mdash; iPhone app, users can have images of Mars delivered daily to their device. The images come from an Arizona State University-designed camera onboard NASA's Mars Odyssey orbiter, and they include every kind of feature there is on the Red Planet.</div> <div>&nbsp;</div> <div>The iPhone app is <a href="http://itunes.apple.com/gb/app/mars-odyssey-themis-image/id371924669?mt=8">available</a> through the iTunes Web site.</div><div>&nbsp;</div> <div>The app comes from Kate Gordon-Bloomfield, a software developer and codirector at <a href="http://www.LittleCollie.com/">LittleCollie Ltd.</a> in the U.K. A programmer for about 10 years, she says, &quot;I became interested in developing software for Apple's mobile platforms after getting an iPhone and MacBook Pro.&quot; She wrote the app on weekends and evenings.</div> <div>&nbsp;</div> <div>Gordon-Bloomfield is also a self-described &quot;complete space nut,&quot; adding, &quot;I have always had an interest in space exploration. I even went to space camp when I was in my teens.&quot;</div> <div>&nbsp;</div> <div><b>From Mars to you</b></div> <div>&nbsp;</div> <div>The camera providing the daily images of Mars is the <a href="http://themis.asu.edu/about"><span style="color: blue;">Thermal Emission Imaging System</span></a>, or THEMIS. It was designed by Philip Christensen, Regent's Professor of geological sciences in the School of Earth and Space Exploration, part of ASU's College of Liberal Arts and Sciences.</div> <div>&nbsp;</div> <div>A multiband instrument, THEMIS makes images of Mars at infrared and visible wavelengths. Its latest accomplishment is the completion of a global portrait of Mars at a resolution of 100 meters (330 feet). Besides being available through the iPhone, the THEMIS images of the day are accessible on the Web at <a href="http://themis.asu.edu/image_of_the_day"><u><span style="color: blue;">http://themis.asu.edu/image_of_the_day</span></u></a>. The site also has links categorizing the Martian features by type.</div> <div>&nbsp;</div> <div><b>On beyond iPhone?</b></div> <div>&nbsp;</div> <div>Choosing to create an app for the iPhone was a natural, says Gordon-Bloomfield, a graduate of ASU who majored in religious studies.</div> <div>&nbsp;</div> <div>&quot;The iPhone, iPod touch, and iPad are a great market,&quot; she says.</div> <div>&nbsp;</div> <div>The Blackberry? Maybe not so much. &quot;While the Blackberry has a large user base,&quot; she says, &quot;its primary focus is enterprise-tier business users. I don't see the THEMIS Mars app as meeting their needs.&quot;</div> <div>&nbsp;</div> <div>What about the Android? Gordon-Bloomfield replies, &quot;The Droid's a budding platform. If its market percentage increases, this app would make a great project for that platform.&quot;</div> <div>&nbsp;</div> <div>Meanwhile, Gordon-Bloomfield is weighing updates. &quot;I've been thinking that loading the images could be improved by loading a lower-quality image initially and then loading higher and higher quality and detail as the user zooms.&quot;</div> <div>&nbsp;</div> <div>Call it Red-Planet-in-Your-Pocket.</div><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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Fri, 18 Jun 2010 19:00:00 +0000rburnham5385 at http://themis.asu.eduMiddle school students find cave on Marshttp://themis.asu.edu/news/middle-school-students-find-cave-mars
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Middle school students find cave on Mars </div>
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Using THEMIS, middle-school science students discover what may be a hole in the roof of a lava tube cave on Mars. </div>
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<p>They went looking for lava tubes on Mars &mdash; and found what may be a hole in the roof of a Martian cave.</p><p>The 16 students in Dennis Mitchell's 7th-grade science class at Evergreen Middle School in Cottonwood, Calif., chose to study lava tubes, a common volcanic feature on Earth and Mars. It was their class project for the <a href="http://msip.asu.edu">Mars Student Imaging Program</a> (MSIP), a component of ASU's <a href="http://marsed.asu.edu">Mars Education Program</a>, which is run at the Mars Space Flight Facility.</p><p>The imaging program involves upper elementary to college students in Mars research by having them develop a geological question to answer about Mars. Then the students actually command a Mars-orbiting camera to take an image to answer their question. Since MSIP began in 2004, more than 50,000 students have participated to varying extents.</p><p>&quot;The students developed a research project focused on finding the most common locations of lava tubes on Mars,&quot; Mitchell said. &quot;Do they occur most often near the summit of a volcano, on its flanks, or the plains surrounding it?&quot;</p><p>To answer the question, the students examined more than 200 images of Mars taken with the <a href="http://themis.asu.edu/about">Thermal Emission Imaging System</a> (THEMIS), an instrument on NASA's <a href="http://mars.jpl.nasa.gov/odyssey">Mars Odyssey</a> orbiter. Philip Christensen, a Regents' Professor of geological sciences in the <a href="http://sese.asu.edu">School of Earth and Space Exploration</a>, is the instrument's designer and principal investigator.</p><p>The students chose for their targeted THEMIS image (plus a secondary backup image) areas on Pavonis Mons volcano that had yet to be photographed by THEMIS at highest resolution (18 meters, or 59 feet, per pixel).</p><p>On their two targeted images the students found lava tubes, as they had hoped. And on the backup image, they also found a small, round black spot. Many Martian lava tubes are marked by aligned chains of collapse pits, which typically have flat floors and sloping sides. The spot the students found, however, appears to have vertical sides.</p><p>Such features made a stir in the news in 2007, when Glen Cushing, a U.S. Geological Survey scientist, published a paper showing several Martian examples, which had been located using the heat-sensing capability of THEMIS. He argued that these holes were anomalous as compared to the usual chain pit crater, being smaller and resembling a relatively straight-sided shaft going down into the ground.</p><p>Cushing proposed that these anomalous pit craters are &quot;skylights&quot; &ndash; places where a small part of the roof of a cave or a lava tube had collapsed, opening the subsurface to the sky. They typically appear cooler than the ground surface by day, but warmer than it by night. This is exactly what would be expected, given that Martian surface temperatures have a large diurnal range, while subsurface temperatures hold fairly even.</p><p>&quot;This pit is certainly new to us,&quot; Cushing told the students. &quot;And it is only the second one known to be associated with Pavonis Mons.&quot; He estimated it to be approximately 190-by-160 meters (620x520 feet) wide and 115 meters (380 feet) deep at least.</p><p>In addition, he said, the spot appears clear against the background surface of Pavonis Mons. &quot;It sticks out like a sore thumb in THEMIS predawn thermal observations.&quot;</p><p>The students have submitted their site as a candidate for imaging by the<span style="text-decoration: underline;"> </span><a href="http://hirise.lpl.arizona.edu">High Resolution Imaging Science Experiment</a> (HiRISE) camera on NASA's <a href="http://mars.jpl.nasa.gov/mro">Mars Reconnaissance Orbiter</a>. HiRISE can image the surface at about 30 centimeters (12 inches) per pixel, which may allow a look inside the hole in the ground.</p><p>&quot;The Mars Student Imaging Program is certainly one of the greatest educational programs ever developed,&quot; Mitchell said.&nbsp; &quot;It gives the students a good understanding of the way research is conducted and how that research can be important for the scientific community. This has been a wonderful experience.&quot;</p><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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Thu, 17 Jun 2010 19:00:00 +0000rburnham5386 at http://themis.asu.eduUpdated THEMIS mosaics of MSL landing site candidateshttp://themis.asu.edu/news/updated-msl-landing-site-mosaics
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Updated THEMIS mosaics of MSL landing sites </div>
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New data from THEMIS is helping scientists choose a landing site for the Mars Science Laboratory (MSL), NASA&#039;s next-generation rover spacecraft, due for launch in 2011. </div>
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<p>New data from THEMIS is helping scientists choose a landing site for the Mars Science Laboratory (MSL), NASA's next-generation rover spacecraft, due for launch in fall 2011.</p> <p>MSL's mission is to assess whether Mars ever was, or is still today, an environment able to support microbial life. To put it another way, the rover's mission is to determine the planet's habitability. MSL will study Martian soil and rock samples and analyze them for organic compounds, the chemical building blocks for life.</p> <p>At a workshop in fall 2009, scientists chose <a href="/files/u3/MSL_Landing_Sites_Final_4.pdf">4 sites (PDF)</a> as possible landing site locations. Since then, several additional sites have been proposed and after further study, one or more may be added to the four already identified. Scientists are collecting data on these sites to evaluate both their scientific merit and engineering feasibility. NASA will chose the final landing site in spring 2011.</p> <p>The site-support work at Arizona State University's Mars Space Flight Facility seeks to improve our understanding of the physical and mineralogical characteristics of the candidate landing sites to help select the best site for MSL. Researchers are preparing THEMIS-derived daytime infrared (IR), nighttime IR, visible, thermal inertia, and decorrelation-stretched mosaics for each MSL candidate site.</p> <p>These mosaics are created in collaboration with Robin L. Fergason of the United States Geologic Survey Astrogeology Science Center in Flagstaff, Arizona.</p> <p>View the <a href="/landingsites">final four candidate sites</a>, plus all the previous candidates. If scientists add sites to the list, they will be added to that page.</p><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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Fri, 26 Mar 2010 22:39:48 +0000rburnham5188 at http://themis.asu.eduNew orbit gives THEMIS better looks at Mars mineralshttp://themis.asu.edu/news/new-orbit-gives-themis-better-looks-mars-minerals
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New orbit yields better Mars mineral maps </div>
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Moving NASA&#039;s Mars Odyssey to a different orbit has increased the sensitivity and efficiency of THEMIS.
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<p>A slow drift in the orbit of NASA's Mars Odyssey spacecraft that mission controllers started nine months ago is now giving an ASU instrument on the spacecraft a better and more sensitive view of minerals on the surface of Mars. The instrument is the Thermal Emission Imaging System (THEMIS), an infrared and visual camera operated by ASU's Mars Space Flight Facility.</p>
<p>The maneuver to change Odyssey's orbit began Sept. 30, 2008, and ended June 9, 2009, with a five-and-a-half-minute thruster firing. The rocket burn fixed the spacecraft's track so that THEMIS looks down on the planet at an earlier time of day, 3:45 in the afternoon instead of 5 p.m.</p>
<p>Odyssey's two-hour orbit is synchronized with the Sun, so that the local solar time on the ground remains the same whatever part of Mars the spacecraft is flying over. As Odyssey travels on its north-to-south leg over the day side, the local time below the spacecraft is now 3:45 pm; similarly, the local time is 3:45 a.m. under the spacecraft as it flies the south-to-north leg of each orbit on the night side.</p>
<p><strong>Warmer ground means better data</strong></p>
<p>"The new orbit means we can now get the type of high-quality data for the rest of Mars that we got for 10 or 20 percent of the planet during the early months of the mission," says Philip Christensen of ASU's School of Earth and Space Exploration, part of the College of Liberal Arts and Sciences. Christensen designed THEMIS and is the instrument's principal investigator.</p>
<p>One important finding based on early-mission THEMIS data was the discovery of <a href="http://themis.asu.edu/news-saltsites">chloride mineral deposits</a> in the ancient southern highlands. These salt beds are possible relics of a warmer and wetter epoch on Mars and may have something to tell scientists about a Martian biosphere, past or present.</p>
<p>"Imaging Mars earlier in the afternoon means that THEMIS sees a warmer surface," explains Christensen. "And this makes a greater temperature difference with the nighttime measurements. The stronger contrast brings out more clearly the composition variations in the surface rocks."</p>
<p>In another operational change, Odyssey has begun in recent weeks to make observations other than straight downward-looking. This more-flexible targeting allows THEMIS to image some latitudes near the poles that never pass directly underneath the orbiter. In addition, the sideways views let THEMIS fill in more quickly gaps in coverage left by previous imaging, and they will also permit stereoscopic, three-dimensional images.</p>
<p>"At visual wavelengths, THEMIS has photographed about half the Martian surface," says Christensen. "We're really looking forward to filling the holes in the coverage."</p>
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NewsTue, 16 Jun 2009 06:00:00 +0000rburnham25 at http://themis.asu.eduTHEMIS lets you find your place on Marshttp://themis.asu.edu/news/themis-lets-you-find-your-place-mars
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THEMIS lets you find your place on Mars </div>
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A new feature in Google Earth 5.0 lets anyone, anywhere suggest places on Mars for THEMIS to photograph. </div>
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<p>&nbsp;Arizona State University researchers and scientists have created two new features for Google Earth 5.0, the popular online application that lets users tour Earth, the starry sky, and the Red Planet Mars.</p><div id="node-23"><div><div><div>The first of the new features lets anyone, anywhere, recommend places on Mars to photograph with ASU's THEMIS camera on NASA's Mars Odyssey orbiter. The second new feature shows the most recent infrared images of Mars sent back to Earth from the THEMIS camera.</div> <div>THEMIS is the Thermal Emission Imaging System, a multiband infrared and visual camera designed at ASU by Dr. Philip Christensen. A Regents' Professor of Geological Sciences in the School of Earth and Space Exploration, Christensen is THEMIS' principal investigator and also director of the Mars Space Flight Facility on the Tempe campus.</div><div>&nbsp;</div> <div>&quot;These two features, developed by our staff in cooperation with programmers at Google, will help everyone have a lot more fun exploring the Red Planet,&quot; says Christensen. &quot;It's public engagement at its best.&quot;</div><div>&nbsp;</div> <div><strong>Hey Mars, say cheese!</strong></div><div>&nbsp;</div> <div>&quot;We wanted to give the general public a way to suggest places on Mars for THEMIS to photograph,&quot; says Christensen. &quot;Using the new feature, people can recommend sites, and these recommendations go to mission scientists who will decide what areas THEMIS images. If a public suggestion matches what the researchers choose, we'll notify the person who suggested the site and let them see the image as soon as we do.&quot;</div><div>&nbsp;</div> <div>To suggest a place for THEMIS to photograph, viewers need two things: Google Earth 5.0 and a file that is updated each week giving the spacecraft's Mars orbital groundtrack. Google Earth 5.0 is available at <a title="http://earth.google.com" href="http://earth.google.com">http://earth.google.com</a>.</div><div>&nbsp;</div> <div>To get the orbital track, users should go to <a title="http://suggest.mars.asu.edu" href="http://suggest.mars.asu.edu">http://suggest.mars.asu.edu</a> and follow the simple steps to register. Registering takes users to a page to download the orbital track file and it also lets them make image suggestions without having to enter an e-mail address with each image suggestion.</div><div>&nbsp;</div> <div>Registering also creates a customized page where users can see their past image suggestions and find links to their successful ones.</div><div>&nbsp;</div> <div>With the orbital track file downloaded, viewers start Google Earth and switch the globe to Mars (via the Planets toolbar button, which resembles the planet Saturn). Then viewers open the orbital track file from within Google Earth. Viewers can also just double-click on the orbital file once Google Earth has been set to Mars as its planet.</div> <div>The places where THEMIS can take images during the coming week appear as stripes wrapped onto the Martian globe. Viewers click on stripe segments to recommend places for THEMIS to photograph.</div><div>&nbsp;</div> <div>&quot;Each viewer can make up to 10 imaging suggestions per week,&quot; says Christian Yates, software engineer at the Mars Space Flight Facility. Yates designed the online interface for the project. If a site picked by a member of the public matches one chosen by the mission scientists, the suggester will be sent a link providing access to the image after it has come from the spacecraft.</div><div>&nbsp;</div> <div>Says Yates, &quot;Making 10 image selections a week, a typical viewer will probably get at least one image.&quot;</div><div>&nbsp;</div> <div>THEMIS takes images at both visual and infrared wavelengths; viewers using Suggest an Image are making recommendations for visual images. These have higher resolutions than THEMIS' infrared ones: 60 feet (18 meters) per pixel versus 330 feet (100 m) per pixel for infrared.</div><div>&nbsp;</div> <div>&quot;Taking pictures with an orbiting satellite can be a complicated business, but this tool makes it much easier,&quot; says Eric Engle, scientific software engineer at the Mars Space Flight Facility and lead project developer for the ASU team. &quot;We hope people enjoy this chance to participate with us in exploring Mars.&quot;</div><div>&nbsp;</div> <div><strong>Live from Mars</strong></div><div>&nbsp;</div> <div>The ASU team also developed, with Google's programmers, a second new Google Earth feature called Live From Mars. It shows the latest infrared images from THEMIS as soon as the mission team at ASU receives them; look for the new feature among the Mars Gallery layers in Google Earth 5.0.</div><div>&nbsp;</div> <div>When the layer is clicked on, viewers see the Martian globe with the most recent THEMIS infrared images displayed on the surface, each flagged with a square symbol. Viewers can zoom in on each image to see details more clearly.</div><div>&nbsp;</div> <div>Mousing over the square symbol brings up the image's identification number, and clicking on the symbol opens a bubble window with more information (such as latitude and longitude, and date and time the photo was taken). The bubble also has links to the THEMIS camera site at ASU and NASA's Mars Odyssey site.</div> <div>THEMIS' designer Christensen notes that both new features let the general public look over the shoulder of Mars researchers &mdash; and Suggest an Image in particular offers a potentially unique reward:</div><div>&nbsp;</div> <div>&quot;Because the coverage of Mars by THEMIS at visual wavelengths is by no means complete,&quot; Christensen says, &quot;some people who recommend an image target could be the first humans ever to see that particular place in such detail.&quot;</div></div></div></div>Wed, 22 Apr 2009 06:00:00 +0000rburnham23 at http://themis.asu.eduSideways look from THEMIS probes Mars atmospherehttp://themis.asu.edu/sideways
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Sideways look from THEMIS probes atmosphere </div>
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On May 25, 2008, the Phoenix lander arrived at Mars and raced to a safe touchdown on the northern plains. At the same time, NASA&#039;s Mars Odyssey orbiter turned its radio antenna to listen for signals from the spacecraft and relayed them to mission controllers on Earth. </div>
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<p>On May 25, 2008, the Phoenix lander arrived at Mars and raced to a safe touchdown on the northern plains. At the same time, NASA's Mars Odyssey orbiter turned its radio antenna to listen for signals from the spacecraft and relayed them to mission controllers on Earth.</p>
<p>As an added benefit of the radio monitoring, an instrument aboard Mars Odyssey, the Thermal Emission Imaging System (or THEMIS), got a chance to take an image profiling the Martian atmosphere as seen above the edge (or limb) of the planet.</p>
<p>In normal operation, THEMIS points straight down at the ground passing below the orbiter. Scientists term this viewing geometry as "nadir-looking," referring to the point opposite the zenith, which is straight overhead.</p>
<p>THEMIS is basically a camera, and its fundamental mission is to image Mars at 10 infrared and five visual "colors." The visual images map the landforms, while the infrared images detect surface temperatures and identify mineral compositions.</p>
<h3>Rock and roll</h3>
<p>To communicate with the Phoenix lander, the location of Odyssey's antenna required mission control to roll and tilt the entire spacecraft so the dish pointed at the ground. And THEMIS (which is bolted to the side of Odyssey) rolled and tilted with it, turning its gaze off toward the limb of Mars, 90 degrees from its usual perspective.</p>
<p>During the roll, THEMIS made the image at right, which sweeps from the cratered surface of Daedalia Planum northward to the visible edge of Mars. It also includes the atmosphere (seen edge on) and the blackness of space.</p>
<p> "Oblique views like these - which we call 'off-nadir images' - suggest an additional role for THEMIS," says Philip Christensen of Arizona State University's School of Earth and Space Exploration. A Regents' Professor of Geological Sciences, Christensen is the director of the Mars Space Flight Facility as well as the designer and principal investigator for THEMIS.</p>
<p>"We would like to take such oblique views more often in the future," he says, noting they can help out in the study of the Martian atmosphere. Such studies are crucial for understanding Mars' weather and climate.</p>
<p>Christopher Edwards, a graduate student at the Mars Space Flight Facility, explains, "We can use THEMIS to map relative temperature differences in the atmosphere, extending from the surface to space. Tracked over months and years, these measurements should give us data on the different sizes of particles caught in the air."</p>
<h3>Fill the gaps</h3>
<p>Sideways viewing offers additional benefits as well, including letting the THEMIS team fill gaps in the visual coverage of the surface.</p>
<p>The global image map of Mars at visual wavelengths still has many blacked-out sections sprinkled across it, where coverage is incomplete. Also, clouds and haze have obscured the ground at times when the spacecraft is flying over.</p>
<p>But with THEMIS operating in nadir-only mode, months or even years may pass before it can re-observe an area on the ground under clear conditions.</p>
<p>"Looking off-nadir - even 20 degrees or less - would make it much easier to fill these gaps," says Christensen.</p>
<h3>Orbit shift?</h3>
<p>NASA is considering new mission rules for Mars Odyssey that would allow THEMIS to point away from the nadir as part of routine operations. If enacted, the rules would go into effect after Mars Odyssey finishes its role as radio relay for Phoenix.</p>
<p>In addition, explains Christensen, NASA is also considering another possible modification: "After the Phoenix mission wraps up this fall, NASA may change the orbit of Mars Odyssey."</p>
<p>This would alter the spacecraft's orbit to pass overhead at 3 p.m. instead of the current 5:30 p.m. time. The result would give significant benefits for THEMIS and the scientists who use its data.</p>
<p>"Changing the orbit to an earlier time of day magnifies the day-night temperature contrast in the surface rocks," says Christensen. Strong temperature differences make it possible for scientists to detect different kinds of rocks on the surface using THEMIS.</p>
<p>Says Christensen, "This would give us a lot better data to carry out the mineral identification part of THEMIS' mission."</p>
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NewsFri, 30 May 2008 06:00:00 +0000cyates117 at http://themis.asu.eduTHEMIS helps Phoenix land safely on marshttp://themis.asu.edu/news/themis-helps-phoenix-land-safely-mars
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THEMIS helps Phoenix land safely on mars </div>
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ASU&#039;s Thermal Emission Imaging System helped scientists find a safe landing site for the Mars Phoenix spacecraft - and the instrument is also giving flight controllers essential data on the atmosphere to ensure a safe touchdown. </div>
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<p>On Sunday, May 25, 2008, the Phoenix spacecraft (a joint project between NASA and the University of Arizona) arrived at Mars after a 10-month cruise from Earth. Traveling initially at 12,500 miles per hour (5.7 kilometers per second), Phoenix made a hair-raising, nail-biting, 6-and-a-half-minute plunge though the Martian atmosphere to a smooth landing on icy dirt not far from the edge of the Red Planet's northern polar cap.</p>
<p>This was territory where no spacecraft had successfully landed. On Earth, the landing site (latitude 68 degrees north, longitude 233 degrees east) would lie not far from the town of Inuvik in Canada's Arctic. On Mars, the site, dubbed "Green Valley," lay on the rolling northern plains. It features water ice at depths of a few inches or centimeters; this ice was the spacecraft's target. The goal of the Phoenix mission was to scrape up some of the icy dirt and analyze it to determine its habitability for microorganisms.</p>
<p>The chosen landing area appeared smooth, flat, and what's most important, relatively free of rocks and boulders. The site's suitability was established in part through surveys by ASU's Thermal Emission Imaging System (THEMIS), a visible and infrared camera on NASA's Mars Odyssey orbiter.</p>
<p>In addition, THEMIS also provided mission controllers with data on the dustiness of the Martian atmosphere. This helped them decide when to open the parachutes and fire the retro-rockets to guide Phoenix to a safe landing.</p>
<h3>Seeking safe harbor</h3>
<p>"THEMIS' main contribution to Phoenix was identifying places where it's safe to land," says Philip Christensen, of Arizona State University's Mars Space Flight Facility in the School of Earth and Space Exploration. A Regents' Professor of Geological Sciences in the College of Liberal Arts and Sciences, Christensen designed THEMIS and is the instrument's principal investigator.</p>
<p>The Phoenix science team chose to land within a latitude band centered on 70 degrees north. Then, says Greg Mehall, mission manager for the Mars Space Flight Facility, "We collected temperature and imaging data sets over that entire band, all around the planet, for the last several years."</p>
<p>Christensen says the THEMIS team studied the region's geology. "We were using the THEMIS data to get a sense of the rock abundance," he says. "Rocks stay warmer at night, so by looking at nighttime infrared temperature data we were able to see warm, rocky areas Phoenix should avoid."</p>
<p>Christensen continues, "We saw a lot of these warm patches, so I raised a small caution. The intended landing areas were looking a good bit rougher than the Gusev and Meridiani landing sites where the Mars Exploration Rovers Spirit and Opportunity had landed."</p>
<p>Then the HiRISE camera on NASA's Mars Reconnaissance Orbiter imaged one of the THEMIS warm areas. "They found these incredible boulder fields," Christensen says. "Half the ground was covered with rocks the size of a kitchen table or bigger."</p>
<p>He continues, "That prompted us to systematically compare HiRISE images to the THEMIS nighttime temperatures. And we found a beautiful correlation between the warm patches and the places with lots of rocks."</p>
<p>Why couldn't the Phoenix team simply use detailed images from HiRISE to pick a site? As Christensen explains, "HiRISE takes very detailed images, but they cover only tiny areas. So there was no hope of imaging all the candidate sites in time."</p>
<p>With a wider field of view, however, THEMIS had little difficulty surveying the entire area, mapping its nighttime temperatures. "What we did," says Christensen, "was take all the THEMIS data, make mosaics of night infrared images, and look for places that were the coldest."</p>
<p>The scientists figured the coldest places probably had the fewest rocks, and those would make good places to start hunting for possible landing sites.</p>
<p>"Using the THEMIS data, we picked a couple of places where you could squeeze in the Phoenix landing ellipse," notes Christensen. "We selected the landing sites, and then HiRISE subsequently imaged those sites and confirmed they indeed have no rocks."</p>
<p>"Together, THEMIS and HiRISE made a great team," he says.</p>
<h3>Something in the air</h3>
<p>Besides landing site selection, THEMIS also helped mission controllers get Phoenix down safely by monitoring the Martian atmosphere. To plan the entry, descent, and landing stages for Phoenix, mission engineers needed to know the winds, density, and temperatures of the atmosphere at all altitudes from space down to the ground.</p>
<p>"For months, we used THEMIS to watch intensively for dust in the atmosphere," says Mehall. "The Phoenix landing team was using a web page we created for them that had constantly updated dust-opacity maps."</p>
<p>A huge global dust storm arose in June 2007, and that kicked atmospheric observations into high gear, says Kim Murray, data archivist at the Mars Space Flight Facility. "THEMIS couldn't see the surface."</p>
<p>THEMIS was designed primarily as a geological instrument, but every image captures atmosphere as well, Murray notes. "We're taking infrared images that record both the surface and whatever is in the atmosphere above the ground," she says. "All of that is in the image."</p>
<p>Since THEMIS began operations in early 2002, Murray explains, scientists have built up a "clear skies" model for the surface. "This allows us to subtract the surface component from the total in an image, and that leaves the atmospheric part," she explains. "The atmospheric component then gets further analyzed to extract the contributions from dust and ice. We also determine what altitude these are at."</p>
<p>After 2007's big dust storm, activity died down, and the atmosphere became a lot quieter and much more transparent as Phoenix' arrival date approached. (See video.)</p>
<p>Says Murray, "Our main support role for the entry, descent, and landing phase was the infrared atmosphere campaign."</p>
<p>It's a role the Mars Space Flight Facility had played before, beginning with the Thermal Emission Spectrometer (TES). This was an infrared-sensing instrument on NASA's Mars Global Surveyor orbiter, which operated from 1996 to 2006. While TES' main mission was mapping the mineralogy of Mars, its wavelength sensitivity let scientists use it to probe the atmosphere as well.</p>
<p>"Our atmospheric knowledge really began with TES," says Murray. "From March to November 2006, THEMIS helped the Mars Reconnaissance Orbiter team with its aerobraking maneuver as the spacecraft first arrived at Mars. At the time, we were lucky to have both TES and THEMIS working. That helped us build up our knowledge of the atmosphere a lot."</p>
<p>Says Christensen, "The good news for Phoenix was that they were landing in the northern spring, which is about the clearest time of year for the atmosphere. The probe got the smooth landing we all wanted."</p>
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phoenixThu, 22 May 2008 06:00:00 +0000cyates118 at http://themis.asu.eduSalt deposits found in Martian highlandshttp://themis.asu.edu/news/salt-deposits-found-martian-highlands
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Salt deposit points to new places to search </div>
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Deposits of chloride (salt) minerals found on Mars using THEMIS may provide evidence for the existence of former Martian life. </div>
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<p>Scientists using a camera designed and operated at Arizona State University's Mars Space Flight Facility have discovered the first evidence for deposits of chloride minerals - salts - in numerous places on Mars. These deposits, say the scientists, show where water was once abundant and may also provide evidence for the existence of former Martian life.</p><p>A team of scientists led by Mikki Osterloo, of the University of Hawaii, used data from the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter to discover and map the Martian chloride deposits. The Jet Propulsion Laboratory in Pasadena, Calif., manages the Mars Odyssey mission for NASA's Science Mission Directorate.</p><p>Developed at Arizona State University, THEMIS is a multi-wavelength camera that takes images in five visual bands and 10 infrared ones. At infrared wavelengths, the smallest details THEMIS can see on the Martian surface are 330 feet (100 meters) wide.</p><p>The scientists found about 200 individual places in the Martian southern hemisphere that show spectral characteristics consistent with chloride minerals. These salt deposits occur in the middle to low latitudes all around the planet within ancient, heavily cratered terrain. The team's report appears in the March 21, 2008 issue of the scientific journal <em>Science</em>.</p><p>Besides Osterloo, the team includes Philip Christensen, Joshua Bandfield, and Alice Baldridge of Arizona State University's Mars Space Flight Facility; Victoria Hamilton and Scott Anderson of the University of Hawaii; Timothy Glotch of Stony Brook University; and Livio Tornabene of the University of Arizona.</p><p>Osterloo found the sites by looking through thousands of THEMIS images processed to reveal, in false colors, compositional differences on the Martian surface. As she explains, &quot;I started noting these sites because they showed up bright blue in one set of images, green in a second set, and yellow-orange in a third.&quot;</p><p>Says team member Christensen, &quot;THEMIS gives us a good look at the thermal infrared, the best part of the spectrum for identifying salt minerals by remote sensing from orbit.&quot; When plotted on a global map of Mars, the chloride sites appeared only in the southern highlands, the most ancient rocks on Mars.</p><h3>Lay of the Land</h3><p>Christensen goes on to characterize the sites' geological setting. &quot;Many of the deposits lie in basins with channels leading into them,&quot; he says. &quot;This is the kind of feature, like salt-pan deposits on Earth, that's consistent with water flowing in over a long time.&quot;</p><p>Christensen, a Regents' Professor of Geological Sciences at ASU's School of Earth and Space Exploration in the College of Liberal Arts and Sciences, designed THEMIS and is the instrument's principal investigator.</p><p>Osterloo notes, &quot;The deposits range in area from about one square kilometer to about 25 square kilometers,&quot; or about 0.4 square mile to about 10 square miles. She adds, &quot;Because the deposits appear to be disconnected from each other, we don't think they all came from one big, global body of surface water.&quot; Instead, she says, &quot;They could come from groundwater reaching the surface in low spots. The water would evaporate and leave mineral deposits, which build up over years.&quot;</p><p>The scientists think the salt deposits formed mostly in the middle to late Noachian epoch, a time that researchers have dated to about 3.9 to 3.5 billion years ago. Several lines of evidence suggest that Mars then had intermittent periods of substantially wetter and warmer conditions than today's dry, frigid climate.</p><h3>Looking for Life</h3><p>Up to now, scientists looking for evidence of past life on Mars have focused mainly on a handful of places that show evidence of clay or sulfate minerals. The reasoning is that clays indicate weathering by water and that sulfates may form by water evaporation. The new research, however, suggests an alternative mineral target to explore for biological remains.</p><p>Says Christensen, &quot;By their nature, salt deposits point to a lot of water, which could potentially remain standing in pools as it evaporates.&quot; That's crucial, he says. &quot;For life, it's all about a habitat that endures for some time.&quot;</p><p>There may also be a concentrating effect, Christensen adds. &quot;The deposits lie in what are probably sedimentary basins. If you look upstream, you might find only a trace of organic materials because they're thinly dispersed.&quot; But over a long period of time, he explains, &quot;The water flowing into a basin can concentrate the organic materials and they could be well preserved in the salt.&quot;</p><p>Whether or not the Red Planet ever had life is the biggest scientific question driving Mars research. On Earth, salt has proven remarkably good at preserving organic material. For example, bacteria have been revived in the laboratory after being preserved in salt deposits for millions of years.</p><p>NASA is currently studying potential landing sites for its Mars Science Laboratory (MSL), a new-generation rover due for launch in fall 2011. Sites featuring clay deposits number heavily in the short-list of candidate places to send the rover.</p><p>Christensen says, &quot;Scientists have studied Martian clay mineral sites for years now, and it's natural they should be considered as targets for the Mars Science Laboratory rover. However, the discovery of chloride minerals in topographic basins within the oldest rocks on Mars should also be considered as an alternative mineralogy for MSL or future rovers to explore.&quot;</p><p>&quot;This discovery demonstrates the continuing value of the Odyssey science mission, now entering its seventh year,&quot; says Jeffrey Plaut, Odyssey project scientist at the Jet Propulsion Laboratory. &quot;The more we look at Mars, the more fascinating a place it becomes.&quot;</p><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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Thu, 20 Mar 2008 06:00:00 +0000cyates119 at http://themis.asu.eduMars image milestone for THEMIS web sitehttp://themis.asu.edu/news/mars-image-milestone-themis-web-site
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Mars image milestone for THEMIS web site </div>
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Lava flows and wind streaks mingle with impact craters in the 1,200th THEMIS Image of the Day. </div>
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<p>The Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter is helping mark a milestone May 4. An image from THEMIS showing Martian lava flows and wind streaks mingling with impact craters, becomes the 1,200th "Image of the Day" posted online at <a href="http://themis.asu.edu/latest" title="http://themis.asu.edu/latest">http://themis.asu.edu/latest</a>.</p>
<p>The Mars Space Flight Facility at Arizona State University operates the site, which is updated every weekday with images and data from THEMIS. The first Image of the Day was posted March 27, 2002.</p>
<p>"We usually select the Image of the Day to show the wide variety of surface features present on Mars," says Kelly Bender, THEMIS mission planner. "Some images, however, are chosen purely for their aesthetic value."</p>
<p>THEMIS is a multi-wavelength camera that photographs the Martian surface in 5 visual and 10 infrared bands. At infrared wavelengths, the smallest details it records are 330 feet (100 meters) wide, while at visual wavelengths - as seen here - the smallest details are 60 feet (18 m) wide.</p>
<p>Image of the Day #1200 shows a strip of ground on Mars that measures 11 miles (18 kilometers) wide by 39 miles (63 km) long.</p>
<p>"We're looking at the Daedalia Planum region," says Bender, "part of the large volcanic province of Tharsis. The lava flows came from the Arsia Mons volcano. Its summit lies about 300 miles, or 500 kilometers, beyond the image frame to the right. The rough textured lava surface traps dust and sand, while the impact craters act as obstacles to the wind."</p>
<p>She notes that the combination of readily available dust and turbulent winds passing the craters creates the bright and dark 'tails' extending to the west (left) of the craters. "These wind streaks indicate the direction the wind was blowing - east to west in this case."</p>
<p>"From the very beginning of the THEMIS project I wanted to bring Mars alive for everyone," says Philip Christensen, Regents' Professor of geological sciences in the School of Earth and Space Exploration, part of ASU's College of Liberal Arts and Sciences. "One of the most enjoyable ways has been to post a new image each day of the mission with a brief description of what we think we are looking at."</p>
<p>Christensen is the director of the Mars Space Flight Facility, and both designer and principal investigator for the THEMIS instrument.</p>
<p>He continues, "Many features we see in these images remain a mystery. More often than not we scratch our heads and mutter 'Wow, what's that?' But that's the fun of exploring Mars, and hopefully those who follow the mission through our images can share in the experience of looking at the unknown for the first time."</p>
<p>THEMIS images are available at themis-data.asu.edu, which lets users search for images by designation or using a map of Mars. Each image is accompanied by data on when the image was taken, where the spacecraft was pointing, the resolution of the image, the local time, and so on. Images can be downloaded in PNG, JPEG, GIF or TIFF formats. Image of the Day #1200 carries the identification designation V23407003.</p>
<p>Mars Odyssey was launched from the Kennedy Space Center in Florida on April 7, 2001, and arrived at Mars on Oct. 24, 2001. The orbiter spent the next several months achieving a circular mapping orbit by aerobraking (dipping into the atmosphere to slow and shrink the orbit). Aerobraking concluded in early February 2002, and primary mapping operations began a few weeks later.</p>
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Fri, 04 May 2007 06:00:00 +0000cyates120 at http://themis.asu.eduGround ice on Mars is patchy and variablehttp://themis.asu.edu/news/ground-ice-mars-patchy-and-variable
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Views show Mars ground ice patchy, variable </div>
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For the first time, scientists have found that water ice lies at variable depths over small-scale patches on the Red Planet.
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<p>For the first time, scientists have found that water ice lies at variable depths over small-scale patches on the Red Planet. The discovery draws a much more detailed picture of underground ice on Mars than was previously available. The new results appear in the May 3, 2007, issue of the scientific journal <i>Nature</i>.</p><p>&quot;We find the top layer of soil has a huge effect on the water ice in the ground,&quot; says Joshua Bandfield, a research specialist in Arizona State University's School of Earth and Space Exploration and sole author of the paper. His findings come from data sent back to Earth by the Thermal Emission Imaging System (THEMIS) on NASA's Mars Odyssey orbiter. THEMIS is a sophisticated camera that takes images in 5 visual bands and 10 heat-sensing (infrared) ones. At infrared wavelengths, the smallest details THEMIS can see on the surface are 330 feet (100 meters) wide. The new results were made using infrared images of several Martian sites, each at a latitude of 60 to 70 degrees, north and south. &quot;These sites are in regions where subsurface water ice is known to exist,&quot; Bandfield says.</p><h3>THEMIS' Sharp View</h3><p>He explains that water ice lying at shallow depths was first detected and mapped by the Gamma Ray Spectrometer (GRS) suite of instruments, also on Mars Odyssey. But, as Bandfield notes, &quot;the smallest patches detectable by GRS are 300 miles, or 500 kilometers, wide.&quot; The new work shows that THEMIS' heat-sensing capability gives scientists a much sharper tool to hunt for buried ice. &quot;Scientists have known for more than a decade that water is on Mars, mostly in the form of ice,&quot; says Philip Christensen of ASU's Mars Space Flight Facility. Christensen, a Regents' Professor of geological sciences at ASU, designed THEMIS but did not participate in this research. &quot;What's exciting is finding out where the ice is in detail and how it got there. We've reached the next level of sophistication in our questions.&quot; Christensen adds, &quot;GRS can probe a meter deep, but it has a giant footprint. Most infrared spectrometers can detect surface ice and ice a few fractions of a millimeter down. THEMIS is sensitive to thermal waves which can penetrate several inches deep - and it can spot details the size of a football field.&quot;</p><h3>Seeking Warmth</h3><p>Bandfield's approach used THEMIS as a thermometer to measure how fast the ground changed temperature during local spring, summer, and fall at the sites. The nature of the surface soil, he says, &quot;makes a big difference in how deep the ice is.&quot; Areas with many rocks at the surface, Bandfield explains, &quot;pump a lot of heat into the ground and increase the depth where you'll find stable ice.&quot; In contrast, he says, dusty areas tend to insulate the ice, allowing it to survive closer to the surface. &quot;These two surface materials - rock and dust - vary widely across the ground, giving underground ice a patchy distribution.&quot; Computer models helped him interpret the temperature observations, he says. &quot;They show areas where water ice would be only an inch or so under the soil, while in other areas ice could lie many feet below the surface.&quot;</p><h3>Mars Climate Cycles</h3><p>Bandfield notes the results fit long-term climatic models for Mars. These show the planet has been both warmer and colder in the past, similar to glacial cycles on Earth. He says, &quot;The fact that ice is present near the depth of stability in the current Martian climate shows that the ground ice is responding to climate cycles.&quot; In turn, he adds, this implies that water ice in the ground can swap places with water vapor in the atmosphere as the climate changes. Bandfield concludes, &quot;The THEMIS measurements support an active water cycle on Mars such as other research has predicted.&quot; &quot;This work has improved our understanding of the water cycle as part of the ongoing exploration of Mars,&quot; says Christensen.</p><h3>Phoenix: Hunting For Ice</h3><p>In August 2007, NASA will launch Phoenix, a mission designed to sample Martian ground ice directly. The Phoenix spacecraft is a non-roving lander that will go to a high-latitude site in Mars' northern hemisphere. Upon landing, it will expose buried ice by scraping away the soil. After collecting a sample of icy soil, Phoenix will analyze its qualities as a possible habitat for microbial life. Says Bandfield, &quot;The take-home message for the Phoenix lander is that the THEMIS results show a lot of patchiness in the ground ice, and this should continue down to smaller and smaller scales.&quot; Phoenix, he adds, &quot;may find ground ice is shallower and much easier to reach in some spots than in others.&quot;</p><fieldset class="fieldgroup group-specialimages"><legend>Special Images</legend><div class="field field-type-filefield field-field-higlight">
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Wed, 02 May 2007 06:00:00 +0000cyates121 at http://themis.asu.eduGas jets spawn dark 'spiders' and spots on Mars icecaphttp://themis.asu.edu/news/gas-jets-spawn-dark-spiders-and-spots-mars-icecap
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Gas jets spawn dark &#039;spiders&#039; and spots </div>
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Every spring it happens. As the Sun peeks above the horizon at the Martian south polar icecap, powerful jets of carbon-dioxide (CO2) gas erupt through the icecap&#039;s topmost layer. The jets climb high into the thin, cold air, carrying fine, dark sand and spraying it for hundreds of feet around each jet.
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<p>Every spring it happens. As the Sun peeks above the horizon at the Martian south polar icecap, powerful jets of carbon-dioxide (CO2) gas erupt through the icecap's topmost layer. The jets climb high into the thin, cold air, carrying fine, dark sand and spraying it for hundreds of feet around each jet.</p>
<p>This dramatic scene emerges from new research by a team of Mars scientists that includes Arizona State University's Phil Christensen. The research report, co-authored with Hugh Kieffer (U.S. Geological Survey, retired) and Timothy Titus (USGS), appears in the August 17, 2006 issue of the scientific journal Nature. The new work solves a longstanding Martian polar riddle.</p>
<p>"If you were there," says Christensen, "you'd be standing on a slab of carbon-dioxide ice." Looking down, you would see dark ground below the 3-foot-thick ice layer. "All around you, roaring jets of CO2 gas are throwing sand and dust a couple hundred feet into the air."</p>
<p>You'd also feel vibration through your spacesuit boots, he says. "The ice slab you're standing on is levitated above the ground by the pressure of gas at the base of the ice."</p>
<h3>Mystery Markings</h3>
<p>The team began its research in an attempt to explain what caused mysterious dark spots, fan-like markings, and spider-shaped features on the icecap at the Martian south pole. The dark spots, typically 50 to 150 feet wide and spaced several hundred feet apart, appear every southern spring as the Sun rises over the icecap. They last for three or four months and then vanish - only to reappear the next year, after winter's cold has deposited a fresh layer of ice on the cap. Most spots even seem to recur at the same locations.</p>
<p>"Originally, scientists thought the spots were patches of warm, bare ground exposed as the ice disappeared," notes Christensen. "But observations made with THEMIS on NASA's Mars Odyssey orbiter told us the spots were nearly as cold as the CO2 ice, which is at -198&deg; Fahrenheit." That finding suggested the spots were just a thin layer of dark material lying on top of the ice and kept chilled by it.</p>
<p>THEMIS is the Thermal Emission Imaging System, a multi-wavelength camera. Christensen, who is a Regents' Professor of Geological Sciences at ASU's new School of Earth and Space Exploration in the College of Liberal Arts and Sciences, designed THEMIS and is the instrument's principal investigator. The new school houses ASU's renowned Mars Space Flight Facility.</p>
<p>Using more than 200 THEMIS visible and infrared images, the team studied one area on the icecap, at 99&deg; east longitude and 86.3&deg; south latitude, from the end of southern winter through mid-summer. The spots began to appear when the Sun was only half a degree high, then quickly became more numerous over several days.</p>
<p>"A few places remained spot-free for more than 100 days," notes Christensen. "Then they developed a large number in a week."</p>
<p>The scientists saw that fan-shaped dark markings didn't form until days or weeks after the spots first appeared, yet some fans grew to half a mile in length. Even more puzzling was the origin of the "spiders," grooves eroded into the surface under the ice. The grooves converge at points directly beneath a spot.</p>
<h3>Icy Greenhouse</h3>
<p>"The key to figuring out the spiders and the spots," says Christensen, "was thinking through a physical model for what was happening." The whole process, he explains, begins during Mars' frigid Antarctic winter, when temperatures drop to -200� F. That's so cold that the Martian air - 95 percent carbon dioxide - freezes out directly onto the surface of the permanent polar cap, which is made of water ice covered with layers of dust and sand.</p>
<p>This seasonal deposit begins as a layer of dusty CO2 frost. Over the winter, the frost recrystalizes and becomes denser, a process called annealing. The dust and sand particles caught in the frost slowly sink. By spring, with the Sun about to rise, the frost layer has become a slab of semi-transparent ice about 3 feet thick, lying on a substrate of dark sand and dust.</p>
<p>Sunlight passing through the slab reaches the dark material and warms it enough that the ice touching the ground sublimates - it turns directly into gas. As days pass and the Sun rises higher, sublimation continues. Before long, the warmed substrate generates a reservoir of pressurized gas under the slab, lifting it off the ground.</p>
<h3>Big Blowout</h3>
<p>Soon after, weak spots in the slab break through, forming narrow vents, and high-pressure gas roars out at speeds of 100 miles per hour or more. Under the slab, the gas erodes the ground as it rushes toward the vents, snatching up loose particles of sand and carving networks of grooves that converge on the vents.</p>
<p>"Once a spider becomes established," says Christensen, "it affects the surface so that a vent will form in the same place the following year."</p>
<p>As they erupt, the jets carry loose sand and particles high in the air. The largest and heaviest particles fall closest to the vent, piling up around it to make the spots. As lighter sand grains tossed out by the jet blow downwind, they create the fans, which can extend tens to hundreds of yards. The lightest particles, meanwhile, drift away on the wind to form a thin layer of dust.</p>
<p>"It's like separating wheat and chaff," explains Christensen. "The finest-grained materials are carried off by the wind, while coarser grains are sifted again and again, year after year."</p>
<p>The vents and jets continue to erupt until the ice slab completely sublimates and vanishes.</p>
<p>This mechanism, says Christensen, "is unlike anything that occurs on Earth."</p>
Wed, 16 Aug 2006 06:00:00 +0000cyates122 at http://themis.asu.eduOrbital eyes picked Mars rover Opportunity's landing sitehttp://themis.asu.edu/news/orbital-eyes-picked-mars-rover-opportunitys-landing-site
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Orbital eyes picked Mars rover&#039;s landing site </div>
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On January 24, 2004 - one Mars year ago - NASA&#039;s Mars Exploration Rover Opportunity arrived at Mars. After a tense, high-speed entry and descent, the rover, tightly cocooned in airbags, bounced and rolled to a stop inside tiny Eagle Crater on Mars&#039; Meridiani Planum. The landing, which made an interplanetary hole-in-one, was flawless. </div>
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<div>On January 24, 2004 - one Mars year ago - NASA's Mars Exploration Rover Opportunity arrived at Mars. After a tense, high-speed entry and descent, the rover, tightly cocooned in airbags, bounced and rolled to a stop inside tiny Eagle Crater on Mars' Meridiani Planum. The landing, which made an interplanetary hole-in-one, was flawless.</div><div>&nbsp;</div><div>A few hours later, Opportunity unpacked itself and turned on a camera. The very first picture captured an outcrop of bedrock - exactly what the spacecraft had been sent millions of miles to find - lying only a few yards away.</div><div>&nbsp;</div><div>If coming to rest inside Eagle Crater was a giant stroke of luck, chance played no role at all in the choice of Meridiani Planum as a landing site. NASA picked Meridiani on the strength of data from two instruments: the Thermal Emission Spectrometer (TES) on the Mars Global Surveyor orbiter and the Thermal Emission Imaging System (THEMIS) on the Mars Odyssey orbiter. Mars Global Surveyor reached Mars in 1997, while Mars Odyssey arrived in 2001.</div><div>&nbsp;</div><div>TES views Mars at wavelengths that isolate and identify rock minerals; each TES pixel covers about 3 by 5 kilometers (2 by 3 miles) on the ground. THEMIS, on the other hand, is a multi-band camera, sensitive to 15 individual colors in the visible and infrared. It can spot details on the ground 18 meters (60 feet) across at visible wavelengths and 100 meters (330 feet) across in the infrared.</div><div>&nbsp;</div><div><b>Touched By Water</b></div><div>&nbsp;</div><div>Looking down from orbit, TES detected an area the size of Illinois rich in a mineral called crystalline gray hematite. On Earth, this iron-oxide mineral usually forms in association with water. Its presence on Mars told mission planners and scientists that Meridiani was an excellent place to send a rover to look for once-wet environments.</div><div>&nbsp;</div><div>&quot;Finding that hematite deposit was one of the shining achievements of TES,&quot; says Phil Christensen of Arizona State University's Mars Space Flight Facility. Christensen, who developed both TES and THEMIS, is a professor of geosciences at ASU and principal investigator for the two instruments. &quot;As far as I was concerned, finding hematite accomplished TES' mission.&quot;</div><div>&nbsp;</div><div>Although TES identified hematite, it took data from THEMIS to clinch the case for a Meridiani landing. Christensen explains, &quot;THEMIS showed what the hematite-bearing unit looked like and that let us map its boundaries. These indicated the hematite most probably formed in a body of standing water and not, for example, from volcanic ash falling from the sky.&quot;</div><div>&nbsp;</div><div>THEMIS then &quot;cemented the deal,&quot; as Christensen puts it, when the instrument's nighttime images showed the site was safe to land on. It was littered neither with large rocks nor extensive patches of dust, two common traps that await Mars landers.</div><div>&nbsp;</div><div><b>Son of TES</b></div><div>&nbsp;</div><div>While the role of TES in choosing a rover landing site is over, the instrument still has an ongoing connection to the Mars rovers. Both Opportunity and Spirit rovers carry a portable version called Mini-TES, short for Miniature Thermal Emission Spectrometer. Christensen is the developer and principal investigator for Mini-TES as well.</div><div>&nbsp;</div><div>In a ground-based echo of what TES did from orbit, Mini-TES acts as a scout for rover scientists. The instrument can look ahead and identify possible targets of mineralogical interest among the outcrops, loose rocks, and soils around the rover. This ability has proved of particular value with the Spirit rover, which is exploring the complex and jumbled geology of the Columbia Hills inside Gusev Crater.</div><div>&nbsp;</div><div>&quot;When Spirit first landed, it was on the lava plains of Gusev,&quot; says Steve Ruff of Arizona State University. He is the scientist now in charge of day-to-day operations with Mini-TES. &quot;The rocks were pretty much all the same - dusty blocks of basalt.&quot;</div><div>&nbsp;</div><div>But when Spirit reached the Columbia Hills, the geological scene changed, becoming far more varied. On numerous occasions, Ruff explains that Mini-TES has guided the rover drivers. Whenever an interesting rock appears in a photo shot by one of the rover's cameras, Mini-TES will spend about 15 minutes taking its spectrum to investigate the rock's mineral content. &quot;We've learned now to look for dark rocks,&quot; says Ruff, noting these are often dust-free.</div><div>&nbsp;</div><div>&quot;If we spot a dark rock with an interesting texture, we'll favor that one over a different dark rock,&quot; explains Ruff. The choosy approach has paid off. In the Columbia Hills, Spirit has found roughly a dozen different rock types, and as Ruff describes it, perhaps two or three times that number await more precise evaluation.</div><div>&nbsp;</div><div>&quot;Every time Mini-TES has said to us, 'Hey, team, there's something worth looking at over there, let's drive to it,' that has paid off in a new rock type,&quot; says Ruff. &quot;Mini-TES has never yet been wrong.&quot;</div><div>&nbsp;</div><div><b>Letting the Minerals Speak</b></div><div>&nbsp;</div><div>Looking back on Opportunity's site selection, Christensen notes, &quot;From the TES and THEMIS perspective, Meridiani really was the mother-lode. It was this incredible beacon screaming out that something unusual happened here. No other place on the planet came even close.&quot;</div><div>&nbsp;</div><div>He adds, &quot;This was the first landing site on any planet that was picked on mineral grounds. The Apollo sites and the previous Mars sites were all based on morphology - what the sites looked like.&quot; If pictures were all anyone used with Meridiani, he says, no one would have chosen to go there.</div><div>&nbsp;</div><div>&quot;Opportunity is an outstanding success,&quot; Christensen says. &quot;A wonderful spacecraft sent to a perfect site.&quot;</div><p>&nbsp;</p><div>Download a&nbsp;<a href="http://www.mars.asu.edu/christensen/docs/christensen_meridiani_jgr_2004.pdf">PDF (816 Kb)</a>&nbsp;of the scientific paper that argued the case for abundant water at Meridiani Planum.</div><div><a href="http://tes.asu.edu">The Thermal Emission Spectrometer (TES)</a>.</div><div><a href="http://themis.asu.edu/about">The Thermal Emission Imaging System (THEMIS)</a>.</div><div><a href="http://minites.asu.edu">The Miniature Thermal Emission Spectrometer (Mini-TES)&nbsp;</a>.</div><div><a href="http://marsrovers.jpl.nasa.gov/home/index.html">Mars Exploration Rover home page</a>.</div>Thu, 01 Dec 2005 07:00:00 +0000cyates123 at http://themis.asu.edu